The invention relates to a pickup mechanism, and in particular to a simplified pickup mechanism for a business machine.
A conventional printer or business machine often comprises an automatic print media feed device. The automatic print media feed device comprises a pickup mechanism, a separating mechanism, a feed mechanism, and an eject mechanism.
In a conventional pickup mechanism, print media sheets are picked up dynamically, wherein a pickup roller continuously provides normal force to the print media sheets, creating friction between the pickup roller and the top print media sheet. Thus, when rotating, the pickup roller can transport the top print media sheet.
Referring to FIG. 1, a conventional pickup mechanism 1 comprises a drive motor 11, a deceleration gear train 12, a switch 13, a first rotating shaft 14, an oscillating arm 15, a one-way device 16, a second rotating shaft 17, and two pickup rollers 18. A rotating shaft of the driving motor 11 is connected to an input end (not shown) of the deceleration gear train 12. The first rotating shaft 14 is connected to an output end (not shown) of the deceleration gear train 12. One end of the oscillating arm 15 is fitted on the first rotating shaft 14 and the other on the second rotating shaft 17. The pickup rollers 18 are respectively fixed to two ends of the second rotating shaft 17. The first rotating shaft 14 is connected to the second rotating shaft 17 through a transmission belt (not shown, disposed in the oscillating arm 15).
Accordingly, when the drive motor 11 operates, initial rotational speed therefrom is reduced to a lower rotational speed by the deceleration gear train 12. The first rotating shaft 14 connected to the deceleration gear train 12 rotates at the lower rotational speed. By the transmission belt, the second rotating shaft 17 also rotates at the lower rotational speed. At this point, the pickup rollers 18 respectively fixed to ends of the second rotating shaft 17 also rotate at the lower rotational speed, thereby transporting the print media sheets (not shown). Moreover, the oscillating arm 15 can oscillate upward and downward about the first rotating shaft 14. The pickup rollers 18 can thus provide a normal force to the print media sheets, creating friction therebetween.
Moreover, the drive motor 11 or deceleration gear train 12, in some conventional business machines, is connected to a feed roller of a feed mechanism. The switch 13, such as a solenoid, switches the operating direction of the driving motor 11.
Referring to FIG. 2, when a pickup sensor 21 in a business machine 2 detects a print media sheet P, the drive motor 11 rotates the pickup rollers 18 counterclockwise, thereby picking up the print media sheet P. When the print media sheet P passes through a feed sensor 22, the feed sensor 22 outputs a signal to the switch 13. At this point, the switch 13 reverses the drive motor 11, such that the deceleration gear train 12 performs reverse reduction output. A feed roller 23 connected to the deceleration gear train 12 rotates clockwise to feed the print media sheet P. The pickup rollers 18, however, are also connected to the decelerating gear train 12. The one-way device 16 prevents the pickup rollers 18 from rotating clockwise when the deceleration gear train 12 performs reverse reduction output. Namely, because of the one-way device 16, the pickup rollers 18 can rotate only counterclockwise. The print media sheet P can thus be ensured in the business machine 2.
Accordingly, as the deceleration gear train 12 is composed of multiple gears, the pickup mechanism 1 is large, adversely affecting application inside the business machine 2 or undesirably increasing the size of the business machine 2 itself. Moreover, because of the deceleration gear train 12, one-way device 16, and switch 13, the pickup mechanism 1 is very complex.